CRYSTALLIZED VARISCITE FROM UTAH. 



By Waldemar T. Schaller 



Of the United States Geological Survey. 



INTRODUCTION. 



The material on wliich the following descriptions are based was 

 collected near Lucin, Utah, by Mr. Douglas B. Sterrett, of the United 

 States Geological Survey, A part of the material consists of well 

 crystallized variscite, a condition so unusual for this mineral that it 

 was at first thought to be a new species. The detailed study has 

 shown, however, that the mineral is identical with variscite, and the 

 quantity of material was sufficient to determine all the chief prop- 

 erties of the mineral. Mr. Sterrett brought out a striking property 

 of tliis mineral by heating a fragment of it before the blowpipe. At 

 a low temperature the vivid green color was readily changed to a 

 deep lavender. The chemical study of the mineral was extended in 

 order to find out if possible the cause of this change, and the various 

 properties of the lavender-colored variscite were studied, as weU as 

 those of the green mineral in order, if possible, to correlate the two. 

 The author wishes to express his thanks to Mr, Sterrett for permission 

 to describe this veiy interesting mineral and for his generosity in fur- 

 nisliing the material needed. The specimens described in this paper 

 are the property of the LTnited States National Museum, (Cat. No. 



86993.) 



OCCURRENCE AND GEM QUALITY. 



The following notes on the occurrence of the variscite near Lucin, 

 Utah, and of the kind and quality of the gem stones have been taken 

 from the manuscript report on the ''Production of precious stones 

 in the United States for 1910," by Douglas B. Sterrett. 



The variscite deposits, about 5 miles northwest of Lucin, Utah, 

 are in the northern part of an irregular-shaped hill, called Utahlite 

 Hill. Utalilite Hill is about a mile long in a northwest-southeast 

 direction and about one-half mile wide. It has an elevation of about 

 5,000 feet above sea level, and rises over 300 feet above the mesas 



Proceedings U. S, National Museum, Vol. 41— No. 1867. 



413 



